Robotic cutting workflow

ABSTRACT

Embodiments of a system and method for surgical tracking and control are generally described herein. A system may include a robotic arm configured to allow interactive movement and controlled autonomous movement of an end effector, a cut guide mounted to the end effector of the robotic arm, the cut guide configured to guide a surgical instrument within a plane, a tracking system to determine a position and an orientation of the cut guide, and a control system to permit or prevent interactive movement or autonomous movement of the end effector.

CLAIM OF PRIORITY

This application is a continuation of U.S. patent application Ser. No.15/795,019, filed on Oct. 26, 2017, which claims the benefit of U.S.Provisional Patent Application Ser. No. 62/414,033, filed on Oct. 28,2016, the benefit of priority of which is claimed hereby, and which isincorporated by reference herein in its entirety.

BACKGROUND

A guide is used in surgery to align a cutting, burring, or sawing devicewith a target object. A cut guide is useful for planning out a cut andallowing for the cut to be precise even in the presence of vibration ormovement of the cutting device. However, the cut guide is sometimesplaced imprecisely due to patient movement, lack of experience, orobstructed visual access.

The use of robotics in surgery is on the rise as more procedures areusing robotics to positively affect surgical outcomes. While techniquesusing robotics to control surgical tools such as cutting devices, thesetechniques sometimes come with high costs, specialized equipment, longersurgical planning times, or longer surgical operation times.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, which are not necessarily drawn to scale, like numeralsmay describe similar components in different views. Like numerals havingdifferent letter suffixes may represent different instances of similarcomponents. The drawings illustrate generally, by way of example, butnot by way of limitation, various embodiments discussed in the presentdocument.

FIG. 1 illustrates a system including a target object and a plurality ofzones in accordance with some embodiments.

FIGS. 2A-2D illustrate a surgical space including a robotic arm and atarget object in accordance with some embodiments.

FIG. 3 illustrates a user interface for a tracking and control system inaccordance with some embodiments.

FIG. 4 illustrates a system for surgical tracking and control inaccordance with some embodiments.

FIG. 5 illustrates a flow chart showing a technique for surgicaltracking and control in accordance with some embodiments.

FIG. 6A illustrates a system showing system state zones in accordancewith some embodiments.

FIG. 6B illustrates a safe zone around a femur and tibia for use with arobotic arm in accordance with some embodiments.

FIGS. 7A-7C illustrate three examples of a safe position for an endeffector of a robotic arm within a femoral sagittal plane in accordancewith some embodiments.

FIGS. 8A-8C illustrate different views of a two slot cut guide inaccordance with some embodiments.

FIGS. 9A-9B illustrate a cutting device used in both slots of a two slotcut guide in accordance with some embodiments.

FIG. 10A illustrates a two slot cut guide used to perform a femoralresection in accordance with some embodiments.

FIG. 10B illustrates a two slot cut guide used to perform a tibialresection in accordance with some embodiments.

FIG. 11 illustrates a flowchart showing a technique for performing asurgical procedure using a two slot cut guide in accordance with someembodiments.

DETAILED DESCRIPTION

As discussed above, a guide may be used to align a cutting, burring, orsawing device with a target object, such as a target bone. Cut guidesare often manually placed by a surgeon on the target object. In otherexamples, cuts are made using fully autonomous robotic cutting devices.The systems and techniques described herein use a robotic arm to controla robotic end effector including a cut guide, burr guide, or saw guide.The robot provides fast accurate positioning of the robotic end effectorallowing the surgeon to focus on completing the procedure with minimalimpact on the patient.

Systems and methods for surgical tracking and control are describedherein. The robotic arm may be used in a surgical field, such as fortotal knee arthroplasty, hip replacement, etc. In an example, the cutguide may be used to precisely align a surgical instrument to make acut, such as on a target bone or other target object. The alignment ofthe robotic end effector may involve a planning system with a userinterface including positioning a representation of the robotic endeffector on a representation of the target object. During the surgicalprocedure, a selectable indication on an intraoperative user interfacemay be used to activate movement the robotic end effector to the plannedalignment position.

The cut guide may be used as a guide for the surgical instrument to makea cut on the target object, such as to align the surgical instrumentwith a specific plane or line. By using a cut guide, a surgeon mayretain control of the surgical instrument while also using the roboticarm to ensure that the surgical instrument is aligned with apredetermined cut plane or cut line. The robot in conjunction with asurgical navigation system allows for repeatable transfer of pre-definedsurgical plan to the patient during the surgical procedure, while stillallowing the surgeon some level of control over the final cuts.

The robotic arm may be tracked by a tracking system (which may includetracking the end effector or the cut guide). The tracking system may beused to determine a location of the cut guide, the end effector, therobotic arm, and the target object, among other things. The robotic armmay be controlled by a control system. The control system may move therobotic arm, such as in response to receiving a selection of theselectable indication on the user interface to move the robotic arm. Therobotic arm may also be moved interactively by the surgeon throughdirect interaction with the end effector, or similar portions of therobotic arm.

A plurality of zones may be established around the target object usingthe tracking system, which maintains a virtual coordinate system aroundthe surgical field. For example, a safety zone around the target objectmay be determined and maintained using the tracking system. Theplurality of zones may include an interaction zone around the safetyzone and a free-drive zone around the interaction zone. The free-drivezone may include an area of the surgical field or an area where therobotic arm is capable of moving, excluding other zones. The interactionzone may include a zone determined based on a selected location. Forexample, the selected location may include a location selected for thecut guide to move to in order to be within a cutting plane or cuttingline or at a cutting position. The interaction zone may include an areasurrounding the selected location (e.g., a few centimeters around theselected location, the selected location including an area capable offitting the cut guide). The interaction zone may exclude a buffer zone,such as the safety zone. The safety zone may be a buffer zoneimmediately surrounding a portion of the target object. For example, ina total knee arthroplasty procedure, the safety zone may include a 20centimeter sphere centered around a proximal end of a patient's femur.The safety zone may include a buffer zone around any portion of apatient. For example, the safety zone may continue (e.g., as a cone orfunnel shape) away from the proximal end of the patient's femur up theremaining portion of the femur.

The robotic arm may be moved or restricted from movement in the zonesaccording to various rules that may change based on a system state. Therobotic arm may be moved autonomously (e.g., moved by the controlsystem), moved interactively (e.g., by a surgeon), or both together(e.g., the surgeon may start an interactive movement, and the controlsystem may control the robotic arm to make the interactive movementeasier or have less resistance). Within certain zones, and in certainsystem states, the robot may restrict motion of the end effector in oneor more directions or limit motion to a single direction or plane.

In an example, a first state may include a startup state beforeautonomous movement to align the cut guide with a cutting plane or line.In the first state, movement may be prevented within (or into) thesafety zone. Movement may be allowed in the interaction zone and thefree-drive zone when the system is in the first state. When the roboticarm is interactively moved into the interaction zone, an autonomousmovement may be initiated. Upon initiation, the control system may movethe robotic arm such that the cut guide is aligned in a cutting plane orline (as previously planned). This autonomous movement may trigger achange to a second system state. In the second system state, movementmay be allowed only along the cutting plane or line. For example,interactive movement of the cut guide up or down along the line or alongthe plane may be permitted. Interactive movement may be preventedoutside the line or plane. In the second state, movement may bepermitted into the free-drive zone or the safety zone from theinteraction zone (e.g., when the cut guide is moved along the cuttingplane or line). Interactive movement in the second state may berestricted to movement along the cutting plane or line. For example,interactive movement may move the cut guide to a position adjacent tothe target object within the safety zone along the cutting plane orline. The cut guide may be pinned to the target object, and a cut may bemade by a cutting device using the cut guide.

After the cut guide is aligned in the cutting plane or line using thecontrol system to move the robotic arm, the cut guide may be locked intoplace. Locking the cut guide may include restricting the cut guide tomovement within the cut guide or plane. In an example, locking the cutguide may include locking the cut guide with respect to the targetobject. For example, if the target object is a target bone and thetarget bone moves, the cut guide may autonomously move to stay withinthe locked position, locked line, or locked plane, with respect to thetarget bone. The plurality of zones may move or change with movement ofthe target object as well. The target object may be tracked by thetracking system to determine changes to the target object location ororientation (e.g., tracked movement). In an example, locking the cutguide may include locking an orientation of the cut guide. Theorientation (or position of the cut guide) may be defined within acoordinate system or with respect to the target object. In anotherexample, a position or orientation of the target object may bedetermined by the tracking system within a coordinate system. In someexamples, the coordinate system maintained by the tracking system ismaintained relative to the target object, so if movement of the targetobject is detected the entire coordinate system shifts accordingly.

FIG. 1 illustrates a system 100 including a target object 102 and aplurality of zones in accordance with some embodiments. The plurality ofzones may include a safety zone 104, an interaction zone 106, and afree-drive zone 108. The plurality of zones may be determined using atracking system. For example, the tracking system may detect a positionor an orientation of the target object 102 (e.g., a bone, a limb, aplurality of bones, a body part, etc.). From the position or theorientation of the target object 102, the tracking system may determinethe plurality of zones. For example, the safety zone 104 may include aminimum distance (e.g., 10 cm, 20 cm, 40 cm, etc.) around the targetobject 102. The minimum distance may be determined based on surgicalinstruments to be used in surgery on the target object 102, appliedforces or movement speed of objects in a surgical field, sensitivity ordurability of the target object 102, power or control of a controlsystem to control objects in a surgical field, or the like. Theinteraction zone 106 may include an area a radial distance away from thesafety zone 104 (e.g., 5 cm, 10 cm, 30 cm, etc.). The free-drive zone108 may include an area outside of the safety zone 104 or theinteraction zone 106.

In an example, a control system may be used to control movement of asurgical instrument or robotic component in a surgical field of thesystem 100. In an example, the control system may allow interactivemovement (e.g., controlled by a surgeon) and prevent autonomous movement(e.g., movement controlled by the control system) within the free-drivezone 108. In an example, the control system may allow interactivemovement or autonomous movement within the interaction zone 106. In anexample, the control system may prevent interactive movement orautonomous movement within the safety zone 104. In another example, thecontrol system may allow movement of an object into the safety zone 104under particular circumstances, as described below.

In an example, a robotic system may perform a commanded movement. Forexample, the robotic system may use sensors on an end effector or otherarea of the robotic arm to detect a manual manipulation of the roboticarm. The robotic arm may then command movement of the robotic armaccording to the manual manipulation. For example, the commandedmovement may include using a motor or control system driver to assist aninteractive movement of the robotic arm. In another example, the roboticsystem may allow for back-driving or manual movement of the endeffector.

The robotic system may perform a commanded movement of the end effectoreither as a defined displacement in its own coordinate system, or as arelative displacement with respect to the target object coordinatesystem. When the robotic system is interfaced with a tracking system(such as an optical tracking system), the coordinates of locations ofinterest may be relayed to the robotic system.

The robotic motion may also occur in response to an applied force on theend effector, such as when the robot has an integrated force-torquesensor. The MedTech ROSA robot, for example, has a force-torque sensorbetween the robot and the end effector. Thus, a force applied to the endeffector (or the cut guide) may result in a corresponding commandedmovement of the robotic arm. Other robots may have force-torque sensorsin one or more joints, and may respond to an applied force anywhere onthe robot arm.

FIGS. 2A-2D illustrate a surgical space 200A-200D including a roboticarm 204 and a target object 202 in accordance with some embodiments. Therobotic arm 204 includes an end effector 206 and a cut guide 208 mountedto the end effector 206 of the robotic arm 204. The cut guide may beused to guide a surgical instrument, such as within a plane or a line.The surgical space 200A may include a plurality of zones, such as asafety zone 210, an interaction zone 212, and a free-drive zone 214.

FIG. 2A shows the surgical space 200A with the robotic arm 204, the endeffector 206, and the cut guide 208 in respective first positions andfirst orientations. The surgical space 200A shows the end effector 206and the cut guide 208 fully in the free-drive zone 214, and no part ofthe end effector 206, the cut guide 208, or the robotic arm 204 are inthe interaction zone 212 or the safety zone 210. In an example, in theorientation shown in FIG. 2A, interactive movement of the robotic arm204 may be permitted. For example, the robotic arm 204, the end effector206, or the cut guide 208 may be moved by a surgeon or other personwithin the free-drive zone 214. A portion of the robotic arm 204 (e.g.,including the end effector 206 or the cut guide 208) may beinteractively moved into the interaction zone 212. Interactive movementinto the safety zone 210 may be prevented (e.g., by a control systemcontrolling the robotic arm 204).

The target object 202, the robotic arm 204, the end effector 206, or thecut guide 208 may be monitored by a tracking system to determine aposition or an orientation of one or more of the components. Thetracking system may establish the safety zone 210, the interaction zone212, or the free-drive zone 214, in the sense that these zones arevirtual geometries within a coordinate system maintained by the trackingsystem. The size and shape of the zones is pre-defined based on aparticular procedure and instruments to be used in the procedure. Thesize and shape of the zones may change during the course of a procedure,such as if the instrument attached to the end effector of the roboticarm changes during the procedure. In an example, the free-drive zone 214may include an area that the robotic arm 204 is capable of moving withinexcluding the interaction zone 212 and the safety zone 210. In anotherexample, the free-drive zone 214 may include an area of the surgicalspace 200A excluding the safety zone 210 and the interaction zone 212(e.g., excluding additional areas the robotic arm 204 may be configuredto move, such as outside the surgical space 200A). The safety zone 210may be established by the tracking system as an area surrounding thetarget object 202. The interaction zone 212 may be established by thetracking system as an area surrounding the safety zone 210. In anexample, interactive movement of the cut guide 208 into the interactionzone 212 may initiate autonomous movement of the robotic arm 204 toposition the cut guide 208 in a cutting position, such as aligned in ancutting plane or a cutting line. In an example, an autonomous movementmay be prevented from moving the end effector 206, the cut guide 208, orthe robotic arm 204 while all three are in the free-drive zone 214.

FIG. 2B shows the surgical space 200B with the robotic arm 204 movedfrom the first position displayed in the surgical space 200A to a secondposition. The robotic arm 204 in the second position remains in thefree-drive zone 214. The surgical space 200B shows the end effector 206and the cut guide 208 moved from the free-drive zone 214 (e.g., when atthe first positions) to second positions within the interaction zone212. In an example, when an interactive movement is attempted to movethe end effector 206, the cut guide 208, or the robotic arm 204 into thesafety zone 210, the interactive movement may be prevented. The movementof the robotic arm 204 from the first position in the surgical space200A to the second position in the surgical space 200B may include aninteractive movement.

After the cut guide 208 is positioned within the interaction zone 212,movement may be prevented or allowed depending on a system state. Forexample, in a first system state, interactive movement may be permittedwithin the interaction zone 212 and the free-drive zone 214. In thefirst system state, autonomous movement may be prevented. When anautonomous movement is activated (e.g., a selectable indication on auser interface is selected or an activation mechanism on the robotic arm204 or elsewhere is activated), a control system may move the roboticarm 204 such that the cut guide is aligned in a cutting position,cutting line, or cutting plane. Selection or activation of theautonomous movement may change the system to a second system state,where autonomous movement is allowed and interactive movement may beprevented. After the cut guide 208 is moved autonomously, the system mayenter a third system state where movement of the cut guide 208 isprevented outside of a locked position, a cutting line, or a cuttingplane. In the third system state, autonomous movement may be allowed tokeep the cut guide 208 in the aligned position (e.g., to keep the cutguide 208 aligned with the target object 202 if the target object 202moves). In the third system state interactive movement may be allowed,such as within the cutting line or cutting plane. The cut guide 208 orthe end effector 206 may be interactively moved into the safety zone 210when the system in is in the third system state (e.g., after the cutguide 208 is autonomously moved to the cutting position, the cuttingline, or the cutting plane).

FIG. 2C shows the surgical space 200C with the robotic arm 204 partiallyin the free-drive zone 214 and partially in the interaction zone 212.The cut guide 208 and the end effector 206 are shown entirely in theinteraction zone 212, although in an example, one or both may bepartially in the interaction zone 212 and partially in the free-drivezone 214. The movement from the second position shown in the surgicalspace 200B of the end effector 206, the cut guide 208, or the roboticarm 204 to a third position shown in the surgical space 200C may includean autonomous movement. For example, a control system may drive the endeffector 206, the cut guide 208, or the robotic arm 204 to the thirdposition or orientation shown in the surgical space 200C. The autonomousmovement may be initiated after the end effector 206, the cut guide 208,or the robotic arm 204 are placed in the interaction zone 212 (e.g., byan interactive movement from the free-drive zone 214). The initiationmay include a selection on a user interface, a selection on a portion ofthe end effector 206, the cut guide 208, or the robotic arm 204, a voicecommand, or the like.

In an example, the surgical space 200C includes a cutting line or acutting plane 216. The cut guide 208 may be aligned with the cuttingline or cutting plane 216. For example, the autonomous movement from thesecond position shown in the surgical space 200B for the cut guide 208to the third position shown in the surgical space 200C may move the cutguide 208 to a cutting position aligned with the cutting line or cuttingplane 216.

FIG. 2D shows the surgical space 200D with the cut guide 208 and the endeffector 206, (and optionally the robotic arm 204) partially in thesafety zone 210 and partially in the interaction zone 212. In anexample, the robotic arm 204 may occupy all three zones. Movement of thecut guide 208 from the cutting position in the interaction zone 212aligned with the cutting line or cutting plane 216 shown in the surgicalspace 200C to the cutting position in the safety zone 210 may be causedby an interactive movement. The cutting position in the safety zone 210may be aligned with the cutting line or cutting plane 216. For example,in the surgical space 200C, the cut guide 208 may be locked to thecutting line or cutting plane 216. Locking the cut guide 208 may includelocking the cut guide 208 to movement only along the cutting line orwithin the cutting plane 216. In an example, the cutting line or cuttingplane 216 may be an absolute cutting line or plane within a coordinatesystem. In another example, the cutting line or cutting plane 216 may bea relative cutting line or plane, where the cutting line or plane isrelative to a position or orientation of the target object 202. Aposition or orientation of the cut guide 208, for example, when in thecutting position or aligned with the cutting line or plane 216, mayinclude a position or orientation relative to the position ororientation of the target object 202.

Movement of the cut guide 208 along the cutting line or plane 216 mayinclude an interactive movement and an autonomous movement together. Forexample, if an interactive movement is initiated to move the cut guide208 from the interaction zone 212 to the safety zone 210, theinteractive movement may include a force that would cause the cut guide208 to move out of the cutting line or plane 216. An autonomous movement(e.g., a force) may be generated by a control system to prevent theinteractive movement from causing the cut guide 208 to leave the cuttingline or plane 216.

The surgical space 200D may include a pin 218. The pin 218 may be usedto secure the cut guide 208 to the target object 202. For example, thecut guide 208 may be secured before a cut is made on the target object202. After the cut guide 208 is secured to the target object 202, thecut guide 208 may be controlled by a control system to move autonomouslyusing the robotic arm 204 in response to movement of the target object202. For example, in response to detecting slight movement of the targetobject 202 (e.g., using a tracking system), the control system maygenerate a small force to move the robotic arm 204 such that the cutguide 208 stays within the cutting line or plane 216 and in a fixedposition relative to the target object. The pin 218 may be used toprevent movement (e.g., accidental interactive movement) of the cutguide 208 along the cutting line or plane 216. In another example, aselection may be made on a user interface to cause the cut guide 208 tobe locked into a final position (e.g., in a coordinate system orrelative to the target object 202). In response to the selection, thetracking system may monitor the target object 202 and the cut guide 208.If any movement of the target object 202 is detected, the control systemmay cause the robotic arm 204 to move the cut guide 208 to keep the cutguide 208 fixed with respect to the target object 202.

FIG. 3 illustrates a user interface 300 for a tracking and controlsystem in accordance with some embodiments. The user interface 300 mayinclude a surgical space viewer 302, which may be virtual or a view froma camera. The surgical space viewer 302 may include a view of a targetbone, one or more zones, and a robotic arm including an end effectorincluding a cut guide. In an example, the surgical space viewer 302 mayupdate a view in real-time.

The user interface 300 may include a cut guide location selectionindication 304. The cut guide location selection indication 304 may beselected to predetermine a position or orientation for the cut guide.The surgical space viewer 302 may be used to select a locking position,cutting position, cutting line, or cutting plane for the cut guide afterthe cut guide location selection indication 304 is selected. Forexample, a user may drag the cut guide representation to a location. Inan example, the user interface 300 may provide a recommended location,line or plane, for example based on previous selections. The surgicalspace viewer 302 may prevent selection of a location within a safetyzone or within a free-drive zone. The surgical space viewer 302 mayallow selection of a location within an interaction zone. For example,the surgical space viewer 302 may highlight or otherwise designate theinteraction zone when the cut guide location selection indication 304 isselected.

The position of the cut guide may be determined by pre-operative orintraoperative planning techniques. Pre-operative planning techniquesmay use imaging (e.g., MRI, X-ray, CT, etc.) to graphically model thepatient's bone. The pre-operative planning technique may be used (suchas by the surgeon) to position a virtual implant on a bone model in theuser interface 300 to visualize or assess implant position prior toperforming cuts. The intraoperative technique may include using anoptical system to register bone landmarks and graphically reconstructthe patient's bone. In an example, the intra-operative technique may beused in combination with pre-operative imaging. The intraoperativeplanning technique may be used to position a virtual implant on the bonemodel to visualize or assess planned cuts (e.g., using the userinterface 300). When the surgeon is satisfied with the plan, the cutplanes may be registered in the robotic system and the robotic arm maybe prompted to position and orient the end effector to achieve plannedcuts (e.g., align the end effector with a cut plane or cut line). Theuser interface 300 may be configured to be used for pre-operativeplanning, intraoperative planning, intraoperative real-time feedback, orpost-operative evaluation. For example, different aspects of the userinterface 300 may be used for planning and real-time feedback to allowthe surgeon to plan and execute a procedure using the end effector andthe robotic arm.

The user interface 300 may include a selectable indication 306, whichupon selection, may cause a control system to move the cut guide. Thecut guide may be moved by the robotic arm autonomously in response tothe selectable indication 306 being selected. In an example, theselectable indication 306 may be unselectable when the cut guide is inthe free-drive zone. In an example, the selectable indication 306 may beselectable only when the cut guide is in the interaction zone. Inanother example, the selectable indication 306 may be selectableregardless of zone, and the control system may autonomously move the cutguide only when the cut guide is first positioned within the interactionzone.

FIG. 4 illustrates a system 400 for surgical tracking and control inaccordance with some embodiments. The system 400 may include a roboticarm 402, a tracking system 408, and a control system 410.

The robotic arm 402 may include an end effector 404, including a cutguide 406 mounted on the end effector 404. The robotic arm 402 may beconfigured to allow interactive movement and controlled autonomousmovement of the end effector 404. The cut guide 406 may be configured toguide a surgical instrument within a line or plane (e.g., a cuttingdevice to cut a target object).

The tracking system 408 may optionally include a camera 412 or aninfrared sensor 414. The tracking system 408 may use the camera 412 orthe infrared sensor 414 to track the robotic arm 402, the end effector404, the cut guide 406, a target object, or the like. In an example, thetracking system 408 may be used to determine a position or anorientation of the cut guide 406. The position or the orientation may bedetermined relative to a coordinate system or relative to a targetobject. An example optical tracking device commonly used for this typeof application is the Polaris Optical Tracking System from NorthernDigital of Waterloo, Ontario, Canada.

The control system 410 may optionally include a user interface 416. Inanother example, the user interface 416 may be separate from the controlsystem 410 or may be communicatively coupled to the control system 410.The control system 410 may be used to determine a zone occupied by thecut guide 406, such as using the position or the orientation of the cutguide, a target object, or a coordinate system. The zone may include asafety zone, an interaction zone, or a free-drive zone. In response todetermining the zone is a free-drive zone, the control system 410 maypermit interactive movement of the end effector 404 and preventautonomous movement of the end effector 404. In response to determiningthe zone is an interactive zone, the control system 410 may permitinteractive movement and autonomous movement of the end effector 404.

The control system 410 may prevent movement (autonomous or interactive)into the safety zone. In an example, the control system 410 may, inresponse to determining that the zone is the interaction zone, causeautonomous movement of the end effector 404 to a cutting position. Theautonomous movement may be caused in response to selection of aselectable indication for the movement on the user interface 416. Theuser interface 416 may be used to select a predetermined cuttingposition, such as a position relative to the target object. In anexample, the control system 410 may disable the selectable indication inresponse to determining the zone is a free-drive zone. In an example,the control system 410 may activate the selectable indication inresponse to determining that the zone is the interaction zone.

After moving the end effector 404 to the cutting position, the cut guide406 may be allowed to move interactively along a cut plane or cut line.The cut guide 406 may be prevented from moving outside of the cut planeor cut line by the control system 410. In an example, the cut guide 406may be permitted to enter the safety zone by the control system 410while the cut guide 406 is in the cut plane or cut line. This permissionmay occur, in an example, only after autonomous movement of the cutguide 406 to the cutting position.

In an example, the control system 410 may lock the cut guide 406 intothe cutting position after causing the cut guide 406 to move to thecutting position. Locking the cut guide 406 may include locking aposition or an orientation of the cut guide 406, locking the cut guideto a cut plane or a cut line, locking the cut guide with respect to acoordinate system, or locking the cut guide with respect to a targetobject (e.g., a position, distance, or orientation of the targetobject).

In an example, the tracking system 408 may determine a trajectory of thecut guide 406, such as from an interactive force applied to the cutguide 406, the end effector 404, or the robotic arm 402. The controlsystem 410 may determine that the trajectory would cause the robotic arm402 or a portion of the robotic arm, the end effector 404, or the cutguide 406 to enter the safety zone. In response to determining that thetrajectory would cause entry into the safety zone, the control system410 may prevent movement of the robotic arm 402.

In an example, the control system 410 may establish the interaction zoneusing anatomical landmarks of the target object (e.g., a target bone) oridentified locations of the target object (e.g., digitized locations).The tracking system 408 may determine a position or an orientation of atarget object relative to the coordinate system. The position or theorientation of the cut guide 406 may be determined relative to theposition or the orientation of the target object by the tracking system.In an example, the coordinate system is determined from the position orthe orientation of the target object.

FIG. 5 illustrates a flow chart showing a technique 500 for surgicaltracking and control in accordance with some embodiments. The technique500 includes an operation 502 to track interactive movement of an endeffector of a robotic arm. The interactive movement may be tracked usinga tracking system. The technique 500 includes an operation 504 todetermine that a cut guide mounted to the end effector of the roboticarm has moved into an interaction zone. The cut guide may be moved froma free-drive zone to the interaction zone. The interaction zone mayinclude an area around a target object, such as a portion of a spherearound the target object. The interaction zone may exclude an areaimmediately surrounding the target object, such as a safety zone.

The technique 500 includes an operation 506 to receive an indication toautonomously move the end effector such that the cut guide is aligned ina cutting plane. The technique 500 includes an operation 508 toautonomously move the end effector such that the cut guide is aligned inthe cutting plane. The technique 500 may include locking the cut guideinto the cutting plane. Locking the cut guide may include locking thecut guide with respect to a coordinate system or a target object. Forexample, the cut guide may be locked into the cutting plane with respectto the target object such that when the target object moves, a controlsystem causes the cut guide to autonomously move with the target object.

The technique 500 may include an operation to determine, such as usingthe tracking system, a trajectory of the cut guide, such as from aninteractive force. The technique 500 may include determining that thetrajectory would cause the robotic arm to enter a safety zone. Thesafety zone may be between the interaction zone and the target object.In response to determining that the trajectory would cause the roboticarm to enter the safety zone, the technique 500 may include preventingmovement of the robotic arm into the safety zone. Preventing themovement may include counteracting the interactive force with anautonomous force from a control system.

The technique 500 may include presenting a user interface, including aselectable indication. The technique 500 may include receiving an inputdirected to the selectable indication. In response to the input, the cutguide may be autonomously moved to the cutting position, such as by acontrol system. In an example, the technique 500 includes disabling theselectable indication in response to determining that the cut guide isin a free-drive zone or activating the selectable indication in responseto determining the cut guide is in the interaction zone.

FIG. 6A illustrates a system 600A showing system state zones inaccordance with some embodiments. The system 600A includes a safety zone602 and an interaction zone 604. The interaction zone 604 may includesubzones, such as specific cutting subzones, specific sawing subzones,specific burring subzones, subzones specific to surgical procedures(e.g., a total knee arthroplasty, a hip replacement, etc.), or the like.The subzones may be preset for a particular procedure. The subzones maybe used for navigating within the interaction zone 604 to initiate aparticular procedure. For example, a surgeon may place an end effectorinto a first subzone to initiate a first procedure, and then move theend effector (e.g., after the procedure has occurred) to a secondsubzone to initiate a second procedure. The first procedure may includean autonomous movement (e.g., to a cutting plane or other alignmentplane), performance of a cut or surgical procedure, and may includeengaging or disengaging the end effector from a target object. After thefirst procedure is complete, the end effector may be moved to a secondsubzone for performance of a second procedure. For example, a total kneearthroplasty often requires multiple cuts in two or more differentplanes. The end effector may be moved to a first subzone for performinga first cut (e.g., after autonomously moving the end effector to align acut guide in a first cutting plane), and then moved to a second subzonefor performing a second cut.

The system 600A illustrates, as an example, three specific subzonesrelated to a total knee arthroplasty. One or more of these subzones maybe used in a total knee arthroplasty. For example, a femur-specificinteraction zone 606, a 4-in-1-specific interaction zone 608, and atibia-specific interaction zone 610 are shown in FIG. 6A. Zones forcutting, burring, or sawing of other joints or body parts may includerespective bone-specific or location-specific zones, and the subzonesare not limited to the three illustrated in FIG. 6A. The specificinteraction zones (e.g., 606-610) may be subzones of the interactionzone, such as for purposes of placing an end effector into the subzones.The subzones may extend into the safety zone, such as for guiding an endeffector after the end effector is locked into a plane or line forcutting, burring, or sawing. The 4-in-1-specific interaction zone 608may be used with a 4-in-1 cut guide, such as those manufactured byZimmer Biomet of Warsaw, Ind. The 4-in-1 cut guide may be used in atotal knee arthroplasty for making finishing cuts. In an example, otherfinishing cut guides may be used in the 4-in-1-specific interaction zone608, which is named herein for convenience and illustration, but mayinclude other cut guides.

In an example, manually moving an end effector into certain zones maytrigger different system surgical states. For example, when the endeffector is brought into the femur-specific interaction zone 606, thesystem may enter a femur resection state. Entering the femur resectionstate may cause a user interface to show a femur resection plan. Whenthe femur resection plan is selected by the user (e.g., a surgeon), theend effector may be moved to align with a cut line or cut plane relatedto the femur resection. In an example, when the end effector is broughtinto the tibia-specific interaction zone 610, the system may enter atibia resection state, which may cause the user interface to show atibia cutting plan. The tibia cutting plan may be selected by the useron the user interface, for example, to move the end effectorautomatically to a tibia cutting plane or line. In an example, when theend effector is brought into the 4-in-1-specific interaction zone 608,the system may enter a 4-in-1 resection state, which may cause the userinterface to show a 4-in-1 cutting plan. The 4-in-1 cutting plan may beselected by the user to move the end effector to a 4-in-1 cut plane orline.

Other interaction zones may be preselected for performing surgicaltechniques. For example, a location for another surgical procedure(e.g., for sawing) may be designated as a sawing interaction zone. Thesawing interaction zone may operate similarly to the other specificinteraction zones 606-610 described above. For example, the sawinginteraction zone may be a subzone of the interaction zone or the sawinginteraction zone may be subject to a safety zone (e.g., where autonomousor interactive movement of the end effector is prevented until after theend effector is autonomously moved into a sawing plane or line).

The surgical states (e.g., femur, tibia, 4-in-1) corresponding to thespecific interaction zones (e.g., 606-610) may be automaticallycontrolled by the position of the end effector. For example, the system600A may automatically enter the femur surgical state when the endeffector is moved (e.g., interactively or via a commanded movement) intothe femur-specific interaction zone 606. Changing to a surgical state(e.g., from a free-drive zone or from another surgical state) may causea user interface to display a selection to move an end effector to apredetermined plane or line corresponding to a surgical actionassociated with the surgical state.

FIG. 6B illustrates a safe zone 614 around a femur 612 and tibia 618 foruse with a robotic arm in accordance with some embodiments. The safezone 614 may include a predetermined distance 616 around the femur, suchas 5 centimeters from the bone (e.g., radially outward from an outsideportion of the bone). In an example, the safe zone 614 may intersectwith the tibia 618. In another example, the safe zone 614 may extendaround the tibia 618 as well. In yet another example, the safe zone 614may go around the tibia 618 and intersect with the femur 612. Thepredetermined distance 616 may be a uniform distance around the femur612, or may increase or decrease with distance from, for example, adistal end of the femur 612.

The safe zone 614 may be used as an area where only autonomous movementof a robotic arm is allowed, which may include resisting interactivemovement (e.g., preventing a surgeon from moving the robotic arm bycountering a force imparted by the surgeon). Alternatively, within thesafe zone 614 the robot may be programmed to ignore interactive inputfrom the surgeon and only respond to commanded (autonomous) movements.The autonomous movement may include movement only within a plane or axis(e.g., a cutting plane or axis) where the robotic arm may have beenmoved into the plane or axis within an interaction zone or some otherzone before the robotic arm autonomously moves into the safety zone 614.In an example, the safety zone 614 may be used to prevent or allow aparticular speed for a robotic arm operating within the safety zone 614.For example, the speed of the robotic arm may be limited when within thesafety zone 614 to a medium or slow speed compared to a fast orunlimited (e.g., subject to the power of the motors controlling therobot) speed when in other zones (e.g., a free drive zone or aninteraction zone). In some examples, the robot may be programmed withincreased sensitivity within the safety zone 614, where the increasedsensitivity includes detecting forces on the end effector. In theseexamples, if the end effector comes into contact with the patient or aninstrument within the safety zone it may be immediately detected and themovement stopped or reversed. Increased sensitivity may be optionallyconfigured and set to different force input settings.

In an example, a robotic arm may be controlled by a controlling devicesuch as a pedal, handheld device, or a user interface of a roboticcontroller. When the controlling device is activated, the robotic armmay enter the safety zone 614, exit the safety zone 614, lock into aplane or axis, or the like. In an example, when the controlling deviceis released, the surgeon operating the controlling device may be askedto reactivate the controlling device when the robotic arm (or a cutguide or end effector of the robotic arm) is outside the safety zone614. When a portion of the robotic arm, such as a cut guide or endeffector is within the safety zone 614, the surgeon may be asked whetherthe cut guide is pinned. When pinned, the robotic arm may be preventedfrom moving. When the cut guide is not pinned, the robotic controllermay restart bone tracking or robotic arm movement (e.g., exit the safetyzone 614).

FIGS. 7A-7C illustrate three examples 700A-700C of a safe position foran end effector of a robotic arm within a femoral sagittal plane inaccordance with some embodiments. FIG. 7B illustrates a femur 702 and atibia 704 in a substantially extended leg position, FIG. 7C illustratesthe femur 702 and the tibia 704 in a substantially bent position, andFIG. 7A illustrates the femur 702 and the tibia 704 in a partially bentposition.

In an example, the femur 702 and the tibia 704 may be used to determinereference lines including for example, a femoral mechanical-anatomical(FMA) axis 710 or a tibial mechanical-anatomical (TMA) axis 712. In anexample, a cutting line or plane may be used to determine a position toperform a cut, such as in a total or partial knee arthroplasty. Forexample, a distal cut line or plane 706 may be used as a cut line orplane for cutting the femur 706. A distal cut plane position 707 may bedefined as a position for a robotic arm to begin to perform a femoralcut on the femur 702. A proximal cut line or plane 708 may be used as acut line or plane for cutting the tibia 704, with a proximal cut planeposition 709 defining a position for the robotic arm to begin to performa tibial cut on the tibia 704. In an example, the distal cut planeposition 707 may represent a first position for a femoral cut and theproximal cut plane position 709 may represent a second position for atibial cut. A cut guide, such as a two slot cut guide (e.g., as shownbelow in FIGS. 8A-8C) affixed to a robotic arm may transition betweenthe first and second positions, as controlled by the robotic arm. Whenthe cut guide is the two slot cut guide, the robotic arm may translatethe cut guide from the first position to the second position (or viceversa) without rotation or with minimal rotation, which may save timeduring the procedure.

The examples 700A-700C illustrate a safety vector 714, at the end ofwhich is a safe position 720. The safe position 720 is selected to avoidcontact between the cut guide, end effector, or instrument and a patientor other instruments (e.g., retractors, bone references, etc). Thesafety vector 714 may be offset from the TMA axis 712 at an angle 718equal to theta divided by ‘y.’ The value ‘y’ may be predetermined suchthat the safety vector 714 or the safe position 720 is adequately offsetfrom the TMA axis 712 or the FMA axis 710. For example, ‘y’ may be setto equal 2 such that the safety vector 714 is halfway from the FMA axis710 to the TMA axis 712 (i.e., the safety vector 714 bisects the anglebetween the FMA axis 710 and the TAM axis 712). In an example, the valueof ‘y’ may be set to other values, such as 4 or ½ such that the safetyvector is closer or further from one of the FMA axis 710 or the TMA axis712, which may be used in a procedure where additional safety is desiredaway from one of the axes 710 or 712. In an example, the safety vector714 may be offset at an angle from the FMA axis 710. An angle theta 716may correspond to the bending angle of the joint of the knee formed bythe angle between the FMA axis 710 and the TMA axis 712. The angle theta716 divided by a value ‘y’ is then used to determine the angel 718, usedto offset the safety vector 714 from the TMA axis 712, away from thefemur 702. The safety vector 714 may have a predetermined distance(e.g., 20 cm), from an intersection of the FMA axis 710 and the TMA axis712. At the end of the safety vector 714, a safety position 720 for therobotic arm may be defined. In an example, a portion of the robotic armmay transition among the safety position 720, the distal cut planeposition 707, and the proximal cut plane position 709. For example, acut guide affixed to an end of the robotic arm may be positioned by therobotic arm (automatically or interactively) at the safety position 720.A procedure may be initiated, and the robotic arm may transition the cutguide from the safety position 720 to the distal cut plane position 707to perform a femoral resection. After the femoral resection iscompleted, the robotic arm may autonomously move the cut guide to theproximal cut plane position 709, and a tibial resection may beperformed. After the tibial resection is completed, the robotic arm mayreturn the cut guide to the safety position 720. In another example, thetibial resection may occur before the femoral resection. In yet anotherexample, the cut guide may optionally be commanded to return to the safeposition 702 between cuts.

In an example, when a procedure is initiated, the robotic arm mayautomatically move a cut guide, end effector, or instrument to the safeposition 720, which is determined based on the femur and tibia position(e.g., angle between their mechanical axes) as described above. Afterthe safe position 720 is reached, the cut guide, end effector, orinstrument may be moved (autonomously or interactively) to the finalcutting position (e.g., the distal cut plane position 707 or theproximal cut plane position 709). When the robotic arm moves the cutguide, end effector, or instrument interactively, the robotic arm maydetermine a plane or axis to approach the distal cut plane position 707or the proximal cut plane position 709 from the safe position 720, andthe speed of the robotic arm may be controlled by a surgeon.

FIGS. 8A-8C illustrate different views 800A-800C of a two slot cut guide804 in accordance with some embodiments. For example, in FIG. 8A, thetwo slot cut guide 804 illustrates a view 800A of the two slot cut guide804 as attached to a robotic arm 802. The two slot cut guide 804includes a first slot 806 and a second slot 808. The two slots may beperpendicular or substantially perpendicular to each other (e.g., withina few degrees of a right angle).

In FIG. 8B, a view 800B illustrates a close-up and sectioned view wherethe distal end of the two slot cut guide 804 is cut off to more clearlyshow the slots 806 and 808. In FIG. 8C, a cross section view is shown ofthe two slot cut guide 804 including the first slot 806 and the secondslot 808.

FIGS. 9A-9B illustrate a cutting device 910 used in both slots (906 and908) of a two slot cut guide 904 in accordance with some embodiments.The two slot cut guide 904 allows the cutting device 910 to be orientedin two different substantially orthogonal orientations without rotationof the cut guide 904 or the robotic arm 902. The two slot cut guide 904may be affixed to a distal end of a robotic arm 902. FIG. 9A illustratesa first view 900A showing a first orientation of the cutting device 910in the second slot 908 of the two slot cut guide 904. FIG. 9Billustrates a second view 900B showing a second orientation of thecutting device 910 in the first slot 906 of the two slot cut guide 904.As shown in these two figures, the cutting device 910 may be insertedinto either slot of the two slot cut guide 904. The cutting device 910may also then be removed from a slot of the two slot cut guide 904 andinserted into the other slot. In another example, two different cuttingdevices may be used for the different slots.

FIG. 10A illustrates a two slot cut guide 1004 used to perform a femoralresection in accordance with some embodiments. FIG. 10B illustrates atwo slot cut guide 1004 used to perform a tibial resection in accordancewith some embodiments. In an example, the two resections may beperformed using the same two slot cut guide 1004. The two slot cut guide1004 may be affixed to a distal end of a robotic arm 1002. FIG. 10Aillustrates a first view 1000A showing a first orientation of thecutting device 1010 in the second slot 1008 of the two slot cut guide1004 to perform a resection of a femur 1012. FIG. 10B illustrates asecond view 1000B showing a second orientation of the cutting device1010 in the first slot 1006 of the two slot cut guide 1004 to perform aresection of a tibia 1014.

In an example, the cutting device 1010 may perform the femoral resectionas shown in the first view 1000A, and be removed from the second slot1008. The robotic arm 1002 may then translate the cut guide 1004 fromthe position shown in the first view 1000A for the femoral resection tothe position shown in the second view 1000B for the tibial resection.The cutting device 1010 may be inserted into the first slot 1006 and thetibial resection may be performed. The translation of the cut guide 1004by the robotic arm 1002 from the position in the first view 1000A to theposition in the second view 1000B may occur without rotation of the cutguide 1004 or the robotic arm 1002, or with only minor rotationaladjustments. Allowing the femoral resection and the tibial resection tobe performed using a single cut guide with a translation of the two slotcut guide 1004 using the robotic arm 1002 without a substantial rotationallows the procedures to be performed more quickly than if rotation of acut guide (e.g., a single slot cut guide) were used or if a second cutguide was used. In another example, two different cutting devices may beused for the resections in the two slots, which may still retain theadvantages described above with respect to rotation and the two slots.In an example, the procedures may be reversed (e.g., the tibialresection and then the femoral resection).

FIG. 11 illustrates a flowchart showing a technique for 1100 performinga surgical procedure using a two slot cut guide in accordance with someembodiments. The technique 1100 includes an operation 1102 to track acut guide affixed to an end effector of a robotic arm. The cut guide mayinclude a two slot cut guide or a cut guide with more than two slots.

The technique 1100 includes a decision operation 1104 to perform a cutguide zone determination. In an example, the decision operation 1104 maybe performed using a tracking system. For example, a tracking system maybe used to track an end effector of a robotic cut guide (e.g., using arobotic controller) and a position or positions of a bone or otherpatient anatomy (e.g., using an optical tracker). The tracking systemmay determine where the end effector is relative to aspects of patientanatomy or absolute positions of either or both the end effector and thepatient anatomy. When the determination indicates the zone is a safetyzone 1106, the technique 1100 includes an operation 1107 to allowautonomous movement only. For example, the robotic arm may resist anymovement other than autonomous movement controlled by a roboticcontroller. An intentional or accidental force, such as by a surgeon,may be resisted or prevented by the robotic arm (e.g., using a counterforce initiated by a robotic controller or by simply not enablingmovement of any robotic joints). In certain examples, the robotic armmay only be moved through commanded movements. In these examples, thecommanded movements may be autonomous or interactive. Within the safetyzone the controller may limit commanded movements to only includeautonomous movements.

When the determination indicates (optionally) that the zone is a freedrive zone 1108, the technique 1100 includes an optional operation 1109to allow interactive movement only (e.g., prevent the robotic arm frommoving autonomously or shutting off power or control to the roboticarm). In an example, interactive movement may include force applied bythe robotic arm, for example in response to an external force (e.g., bya surgeon) on the arm, as a force assist, but may not include autonomous(e.g., without the external force) movement.

When the determination indicates the zone is an interaction zone 1110,the technique 1100 includes an operation 1112 to allow autonomousmovement or interactive movement. For example, when an end effector at adistal end of a robotic arm is in the interaction zone 1110, movementmay be controlled by a robotic controller or a surgeon manipulating therobotic arm.

The technique 1100 includes an operation 1114 to autonomously move theend effector such that a first slot of the cut guide is aligned in afirst cutting plane. Operation 1114 may be performed in response todetermining that the interactive movement has caused the cut guide tomove into the interaction zone. The end effector may be arranged suchthat a first slot of the cut guide is aligned in a first cutting plane.In an example, the first cutting plane is a femoral distal cut plane. Inan example, the first slot is configured to receive the surgicalinstrument to perform a femoral distal cut along the first cuttingplane. The technique 1100 includes an operation 1116 to determine that afirst resection has been completed. The first resection may be completedusing a surgical instrument inserted into the first slot of the cutguide.

The technique 1100 includes an operation 1118 to autonomously move theend effector such that a second slot of the cut guide is aligned in asecond cutting plane. In an example, the technique 1100 may includedetermining that a second resection has been completed, may includeremoving the end effector to the free drive zone 1108 or the interactionzone 1110. In an example, operations 1114, 1116, and 1118 may beinitiated only when the robot is within the interaction zone 1110, butmay actually take place within the safety zone 1106.

The end effector may be autonomously moved, for example in response todetermining that the first resection has been completed. The endeffector may be arranged such that a second slot of the cut guide isaligned in a second cutting plane after being autonomously moved (e.g.,by the robotic arm controlled by a robotic controller).

In an example, moving the end effector may include aligning the secondslot of the cut guide in the second cutting plane, such as bytranslating the end effector without rotating the end effector. Forexample, the end effector may be translated without rotating from aposition where the first slot of the cut guide was aligned in the firstcutting plane to a position where the second slot of the cut guide isaligned in the second cutting plane. In an example, the second cuttingplane is a tibial proximal cut plane. The second slot may be configuredto receive the surgical instrument (or a second surgical instrument) toperform a tibial proximal cut along the second cutting plane. In anotherexample, the first slot and the second slot are arranged orthogonally toeach other on the cut guide.

In an example the term “machine readable medium” may include a singlemedium or multiple media (e.g., a centralized or distributed database,or associated caches and servers) configured to store one or moreinstructions. The term “machine readable medium” may include any mediumthat is capable of storing, encoding, or carrying instructions forexecution by a machine and that cause the machine to perform any one ormore of the techniques of the present disclosure, or that is capable ofstoring, encoding or carrying data structures used by or associated withsuch instructions. Non-limiting machine readable medium examples mayinclude solid-state memories, and optical and magnetic media. Specificexamples of machine readable media may include: non-volatile memory,such as semiconductor memory devices (e.g., Electrically ProgrammableRead-Only Memory (EPROM), Electrically Erasable Programmable Read-OnlyMemory (EEPROM)) and flash memory devices; magnetic disks, such asinternal hard disks and removable disks; magneto-optical disks; andCD-ROM and DVD-ROM disks.

Example 1 is a system for surgical tracking and control comprising: arobotic arm configured to allow interactive movement and controlledautonomous movement of an end effector; a cut guide mounted to the endeffector of the robotic arm, the cut guide configured to guide asurgical instrument within a plane; a tracking system to determine aposition and an orientation of the cut guide relative to a coordinatesystem; and a control system to: determine a zone occupied by the cutguide using at least the position of the cut guide; in response todetermining the zone is a free-drive zone, permit interactive movementof the end effector and prevent autonomous movement of the end effector;and in response to determining the zone is an interaction zone, permitinteractive movement and autonomous movement of the end effector.

In Example 2, the subject matter of Example 1 includes, wherein thecontrol system is further to cause, in response to determining the zoneis the interaction zone, autonomous movement of the end effector to acutting position.

In Example 3, the subject matter of Example 2 includes, wherein, aftermoving to the cutting position, the cut guide is allowed to move along acut plane and prevented from moving outside of the cut plane.

In Example 4, the subject matter of Example 3 includes, wherein the cutguide is allowed to enter a safety zone while in the cut plane.

In Example 5, the subject matter of Examples 2-4 includes, wherein thecontrol system is to lock the cut guide into the cutting position aftercausing the cut guide to move to the cutting position.

In Example 6, the subject matter of Example 5 includes, wherein thecontrol system is to move the cut guide relative to a tracked movementof a target object when the cut guide is locked, such that the cut guideis locked into the cutting position relative to the target object.

In Example 7, the subject matter of Examples 5-6 includes, wherein tolock the cut guide into the cutting position, the control system is tolock the cut guide into the cutting position in response to receiving aselection via a user interface.

In Example 8, the subject matter of Examples 2-7 includes, wherein thecontrol system is to lock the cut guide into the cutting position afterinteractive positioning of the cut guide, the interactive positioningoccurring after the autonomous movement.

In Example 9, the subject matter of Examples 2-8 includes, wherein thecontrol system further comprises a user interface, the user interfaceincluding a selectable indication that upon selection, causes thecontrol system to autonomously move the cut guide to the cuttingposition.

In Example 10, the subject matter of Example 9 includes, wherein thecutting position is a predetermined cutting position selected by asurgeon relative to a target object.

In Example 11, the subject matter of Examples 9-10 includes, wherein thecontrol system is to: in response to determining the zone is thefree-drive zone, disable the selectable indication; and in response todetermining the zone is the interaction zone, activate the selectableindication.

In Example 12, the subject matter of Examples 1-11 includes, wherein thecontrol system is to established the interaction zone using anatomicallandmarks of a target bone.

In Example 13, the subject matter of Examples 1-12 includes, wherein thetracking system is further to determine a position and an orientation ofa target object relative to the coordinate system.

In Example 14, the subject matter of Example 13 includes, wherein theposition and the orientation of the cut guide are determined relative tothe position and the orientation of the target object and wherein thecoordinate system is determined from the position and the orientation ofthe target object.

In Example 15, the subject matter of Examples 1-14 includes, wherein thecut guide includes a first slot and a second slot, the first slot andthe second slot configured to receive a surgical instrument, and whereinthe control system is further to control the robotic arm to navigate thecut guide from a first position within the interaction zone to a secondposition within the interaction zone, the first position aligning thefirst slot with a first cut plane and the second position aligning thesecond slot with a second cut plane.

In Example 16, the subject matter of Example 15 includes, wherein tonavigate the cut guide, the control system is to translate the cut guidewithout rotating the cut guide.

In Example 17, the subject matter of Examples 15-16 includes, whereinthe first cut plane is a femoral distal cut plane, wherein the firstslot is configured to receive the surgical instrument to perform afemoral distal cut when in the first position, wherein the second cutplane is a tibial proximal cut plane, and wherein the second slot isconfigured to receive the surgical instrument to perform a tibialproximal cut when in the second position.

In Example 18, the subject matter of Examples 15-17 includes, whereinthe first slot and the second slot are arranged orthogonally.

Example 19 is a method for surgical tracking and control, the methodcomprising: tracking, using a tracking system, interactive movement ofan end effector of a robotic arm; determining, using the trackingsystem, whether the interactive movement has caused a cut guide mountedto the end effector of the robotic arm to move into an interaction zone;receiving an indication to autonomously move the end effector such thatthe cut guide is aligned in a cutting plane; and autonomously moving, inresponse to determining that the interactive movement has caused the cutguide to move into the interaction zone, the end effector such that thecut guide is aligned in the cutting plane.

In Example 20, the subject matter of Example 19 includes, locking thecut guide into the cutting plane and moving the cut guide relative to atracked movement of a target object when the cut guide is locked, suchthat the cut guide is locked into the cutting plane relative to thetarget object.

In Example 21, the subject matter of Examples 19-20 includes,determining a trajectory of the cut guide from an interactive force;determining that the trajectory would cause the robotic arm to enter asafety zone; and in response to determining the trajectory would causethe robotic arm to enter the safety zone, preventing movement of therobotic arm into the safety zone.

In Example 22, the subject matter of Examples 19-21 includes, whereinautonomously moving the end effector such that the cut guide is alignedin the cutting plane includes aligning a first slot of the cut guidewith the cutting plane; and further comprising: receiving an indicationto autonomously move the end effector such that a second slot of the cutguide is aligned in a second cutting plane; and autonomously moving theend effector such that the second slot of the cut guide is aligned inthe second cutting plane.

In Example 23, the subject matter of Example 22 includes, wherein thefirst slot and the second slot of the cut guide are orthogonal, andwherein autonomously moving the end effector such that the second slotof the cut guide is aligned in the second cutting plane includesautonomously translating the end effector from a position within theinteraction zone such that the cut guide is aligned in the cutting planeto a position within the interaction zone such that the second slot ofthe cut guide is aligned in the second cutting plane without rotatingthe end effector.

Example 24 is at least one machine-readable medium includinginstructions for operation of a surgical tracking and control system,which executed by a processor, cause the processor to perform operationsto: track, using a tracking system, interactive movement of an endeffector of a robotic arm; determine, using the tracking system, whetherthe interactive movement has caused a cut guide mounted to the endeffector of the robotic arm to move into an interaction zone; receive anindication to autonomously move the end effector such that the cut guideis aligned in a cutting plane; and autonomously move, in response todetermining that the interactive movement has caused the cut guide tomove into the interaction zone, the end effector such that the cut guideis aligned in the cutting plane.

In Example 25, the subject matter of Example 24 includes, instructionsto present a user interface, the user interface including a selectableindication, which when selected, causes the processor to performoperations to autonomously move the end effector such that the cut guideis aligned in the cutting plane.

In Example 26, the subject matter of Example 25 includes, instructionsto: disable, in response to determining the end effector has moved intoa free-drive zone, the selectable indication; and activate, in responseto determining the end effector has moved into the interaction zone, theselectable indication.

Example 27 is a system for surgical tracking and control comprising: arobotic arm configured to allow interactive movement and controlledautonomous movement of an end effector; a cut guide mounted to the endeffector of the robotic arm, the cut guide having a first slot and asecond slot, the first slot and the second slot configured to receive asurgical instrument; a tracking system to determine a position and anorientation of the cut guide relative to a coordinate system; and acontrol system to: control the robotic arm to navigate the cut guideinto a first position, and from the first position to a second position,the first position aligning the first slot with a first cut plane andthe second position aligning the second slot with a second cut plane.

In Example 28, the subject matter of Example 27 includes, wherein tonavigate the cut guide from the first position to the second position,the control system is to translate the cut guide without rotating thecut guide.

In Example 29, the subject matter of Examples 27-28 includes, whereinthe first cut plane is a femoral distal cut plane, and wherein the firstslot is configured to receive the surgical instrument to perform afemoral distal cut when in the first position.

In Example 30, the subject matter of Examples 27-29 includes, whereinthe second cut plane is a tibial proximal cut plane, and wherein thesecond slot is configured to receive the surgical instrument to performa tibial proximal cut when in the second position.

In Example 31, the subject matter of Examples 27-30 includes, whereinthe first cut plane and the second cut plane are orthogonal.

In Example 32, the subject matter of Examples 27-31 includes, whereinthe control system is further to use information captured by a camera todetect that the resection has been completed.

In Example 33, the subject matter of Examples 27-32 includes, whereinthe control system is further to: cause, in response to determining thecut guide is in an interaction zone, autonomous movement of the cutguide to the first position using the robotic arm, wherein the firstposition is within a safety zone.

Example 34 is a method for surgical tracking and control, the methodcomprising: determining, using a tracking system, whether interactivemovement has caused a cut guide mounted to an end effector of a roboticarm to move into an interaction zone; autonomously moving, in responseto determining that the interactive movement has caused the cut guide tomove into the interaction zone, the end effector such that a first slotof the cut guide is aligned in a first cutting plane; determining that afirst resection has been completed using a surgical instrument insertedinto the first slot of the cut guide; autonomously moving, in responseto determining that the first resection has been completed, the endeffector such that a second slot of the cut guide is aligned in a secondcutting plane.

In Example 35, the subject matter of Example 34 includes, whereinautonomously moving the end effector such that the second slot of thecut guide is aligned in the second cutting plane includes translatingthe end effector without rotating the end effector from a position suchthat the first slot of the cut guide is aligned in the first cuttingplane to a position such that the second slot of the cut guide isaligned in the second cutting plane.

In Example 36, the subject matter of Examples 34-35 includes, whereinthe first cutting plane is a femoral distal cut plane, wherein the firstslot is configured to receive the surgical instrument to perform afemoral distal cut along the first cutting plane, wherein the secondcutting plane is a tibial proximal cut plane, and wherein the secondslot is configured to receive the surgical instrument to perform atibial proximal cut along the second cutting plane.

In Example 37, the subject matter of Examples 34-36 includes, whereinthe first slot and the second slot are arranged orthogonally to eachother on the cut guide.

In Example 38, the subject matter of Examples 34-37 includes, whereindetermining that the first resection has been completed includesreceiving a user indication that the first resection has been completed.

In Example 39, the subject matter of Examples 34-38 includes, whereindetermining that the first resection has been completed includes usinginformation captured by a camera to detect that the resection has beencompleted.

In Example 40, the subject matter of Examples 34-39 includes, causing,in response to determining the cut guide is in an interaction zone,autonomous movement of the cut guide to the first position using therobotic arm, wherein the first position is within a safety zone.

Example 41 is at least one non-transitory machine-readable mediumincluding instructions for operation of a surgical tracking and controlsystem, which executed by a processor, cause the processor to performoperations to: determine, using a tracking system, whether interactivemovement has caused a cut guide mounted to an end effector of a roboticarm to move into an interaction zone; autonomously move, in response todetermining that the interactive movement has caused the cut guide tomove into the interaction zone, the end effector such that a first slotof the cut guide is aligned in a first cutting plane; determine that afirst resection has been completed using a surgical instrument insertedinto the first slot of the cut guide; autonomously move, in response todetermining that the first resection has been completed, the endeffector such that a second slot of the cut guide is aligned in a secondcutting plane.

In Example 42, the subject matter of Example 41 includes, wherein toautonomously movie the end effector such that the second slot of the cutguide is aligned in the second cutting plane, the instructions cause theprocessor to translate the end effector without rotating the endeffector from a position such that the first slot of the cut guide isaligned in the first cutting plane to a position such that the secondslot of the cut guide is aligned in the second cutting plane.

In Example 43, the subject matter of Examples 41-42 includes, whereinthe first cutting plane is a femoral distal cut plane, wherein the firstslot is configured to receive the surgical instrument to perform afemoral distal cut along the first cutting plane, wherein the secondcutting plane is a tibial proximal cut plane, and wherein the secondslot is configured to receive the surgical instrument to perform atibial proximal cut along the second cutting plane.

In Example 44, the subject matter of Examples 41-43 includes, whereinthe first slot and the second slot are arranged orthogonally to eachother on the cut guide.

In Example 45, the subject matter of Examples 41-44 includes, wherein todetermine that the first resection has been completed, the instructionscause the processor to receive a user indication that the firstresection has been completed.

In Example 46, the subject matter of Examples 41-45 includes, wherein todetermine that the first resection has been completed, the instructionscause the processor to use information captured by a camera to detectthat the resection has been completed.

Example 47 is at least one machine-readable medium includinginstructions that, when executed by processing circuitry, cause theprocessing circuitry to perform operations to implement of any ofExamples 1-46.

Example 48 is an apparatus comprising means to implement of any ofExamples 1-46.

Example 49 is a system to implement of any of Examples 1-46.

Example 50 is a method to implement of any of Examples 1-46.

Method examples described herein may be machine or computer-implementedat least in part. Some examples may include a computer-readable mediumor machine-readable medium encoded with instructions operable toconfigure an electronic device to perform methods as described above. Animplementation of such methods may include code, such as microcode,assembly language code, a higher-level language code, or the like. Suchcode may include computer readable instructions for performing variousmethods. The code may form portions of computer program products.Further, in an example, the code may be tangibly stored on one or morevolatile, non-transitory, or non-volatile tangible computer-readablemedia, such as during execution or at other times. Examples of thesetangible computer-readable media may include, but are not limited to,hard disks, removable magnetic disks, removable optical disks (e.g.,compact disks and digital video disks), magnetic cassettes, memory cardsor sticks, random access memories (RAMs), read only memories (ROMs), andthe like.

1. A system for surgical tracking and control comprising: a robotic armconfigured to allow interactive movement and execute controlledautonomous movement of an end effector; a cut guide mounted to the endeffector of the robotic arm, the cut guide configured to guide asurgical instrument within a plane; a tracking system configured todetermine a position and an orientation of the cut guide relative to acoordinate system; and a control system configured to: automaticallymake a determination that the cut guide is in a cutting position oraligned with a cutting line or a cutting plane based on the position; inresponse to said determination, permit interactive movement of the endeffector and prevent autonomous movement of the end effector.
 2. Thesystem of claim 1, wherein the control system is further configured to,after receiving an indication to activate autonomous movement, cause, inresponse to said determination indicating the cut guide is aligned withthe cutting line or the cutting plane, autonomous movement of the endeffector to the cutting position.
 3. The system of claim 2, wherein,after moving to the cutting position, the cut guide is furtherconfigured to be moveable along the cutting plane and to be preventedfrom moving outside of the cutting plane.
 4. The system of claim 3,wherein the cut guide is further configured to be allowed to enter asafety zone while in the cutting plane.
 5. The system of claim 2,wherein the control system is further configured to lock the cut guideinto the cutting position after causing the cut guide to move to thecutting position.
 6. The system of claim 5, wherein the control systemis further configured to move the cut guide relative to a trackedmovement of a target object when the cut guide is locked, such that thecut guide is locked into the cutting position relative to the targetobject.
 7. The system of claim 5, wherein to lock the cut guide into thecutting position, the control system is further configured to lock thecut guide into the cutting position in response to receiving a selectionvia a user interface.
 8. The system of claim 2, wherein the controlsystem is further configured to lock the cut guide into the cuttingposition after interactive positioning of the cut guide, the interactivepositioning occurring after the autonomous movement.
 9. The system ofclaim 2, wherein the control system further comprises a user interface,the user interface including a selectable indication that uponselection, causes the control system to autonomously move the cut guideto the cutting position.
 10. The system of claim 9, wherein the cuttingposition is a predetermined cutting position selected by a surgeonrelative to a target object, the predetermined cutting position aligninga first slot of the cut guide with a cut plane.
 11. The system of claim9, wherein the control system is further configured to: in response tosaid determination, activate the selectable indication.
 12. The systemof claim 1, wherein the control system is further configured toestablish the interaction zone using anatomical landmarks of a targetbone.
 13. The system of claim 1, wherein the tracking system is furtherconfigured to determine a position and an orientation of a target objectrelative to the coordinate system.
 14. The system of claim 13, whereinthe position and the orientation of the cut guide are determinedrelative to the position and the orientation of the target object andwherein the coordinate system is determined from the position and theorientation of the target object. 15.-20. (canceled)